Aiming at the complicated engineering problems of the straight beam type flexible hinges damage position and the degree of damage，a new method of damage identification of straight beam type flexible hinge based on AHP was proposed. ANSYS Workbench was used to conduct finite element analysis of straight beam type flexible hinge,and the stress cloud figure was obtained，so the location of the damage was found.Then AHP was used to modeling.The damage vector was simulated by the influence of damage factors on the damage location. The example shows that this method can quantitatively identify the hinge damage，and the accuracy is more than 90%. For some equipment maintenance,the method has a certain engineering guiding significance.